Novel interpolymer blends

ABSTRACT

Disclosed herein are polymer blends comprising a first interpolymer of a vinyl alcohol ester and at least one ethylenically unsaturated acid ester and a second interpolymer comprising a vinyl aromatic compound, at least one ethylenically unsaturated acid ester and at least one compound containing one or more acid groups. These blends are particularly useful as zinc oxide binders. The polymer blends are also useful as adhesives and coatings for such substrates as paper, glass and metal foil.

I Un ted States Patent u 13,607,376

[72] lnventors Robert 3- Blame 7 ,973,165 2/1961 Kaszuba et al...117/161 X Eastbongmeadow; 2,976,148 3/1961 Walford 117/161 X Davld R.Cahlll, Wllbralmn; Peter 3,037,955 6/1962 Carman 117/161 XWaclteLSprhglleld, allot Mass. 3,202,638 8/1965 Van Ess 117/161 X [21]App]. No. 783,700 3,282,876 11/1966 Williams ct al. 117/161 X [22] FiledDec. 13, 1968 3,477,975 11/1969 Concannon 1 17/161 X [45) Patented Sept.21, 197! Pm" ary Examiner-William D. Martln [73] gir a AssistantExaminer-M. R. Lusignan Attorneys-James L. Lewis, Arthur E. Hoffman andH. B. Roberts [54] NOVEL INTERPOLYMER ILENDS V I 7 V m l I l 1 China, NoDrawings [52] US. U. s.

- 1 17/161 UT ABSTRACT: Disclosed herein are polymer blends comprising[51] hi. 3 27/ a first interpolymer of a vinyl alcohol ester and atleast one Dzlh ethylenically unsaturated acid ester and a second interlpoIymer comp igins a vinyl aromatic compound at least one UA, 16 U I24132 C;260/901 i ethylenically unsaturated acid ester and at least onecompound containing one or more acid groups. These blends are [56] cmparticularly useful as zinc oxide binders. The polymer blends UNITEDSTATES PATENTS are also useful as adhesives and coatings for suchsubstrates as paper, glass and metal foil.

NOVEL INTERPOLYMER BLENDS BACKGROUND OF THE INVENTION I. Field of theInvention This invention relates to novel blends of interpolymers whichare useful as binders and adhesives. More particularly, this inventionrelates to blends of a first interpolymer comprising a vinyl alcoholester and at least one ethylenically unsaturated acid ester and a secondinterpolymer comprising a vinylidene aromatic compound, at least oneethylenically unsaturated acid ester and at least one ethylenicallyunsaturated compound containing at least one acid group.

2. Description of the Prior Art Electrophotography relates to substrateshaving a photoconductive substance coated thereon which provides asurface upon which images are reproducible. The substrate may, forexample, be paper, glass, metal foil, etc. The photoconductive substanceis a material having electrical conductivity dependent upon the amountof light to which it is subjected. The photoconductive layer, althoughnot light sensitive per se, is rendered so by applying to the coatedarticle an electrostatic charge (e.g. by Corona discharge). Images to bereproduced are placed on top of the charged surface which is exposed toillumination by conventional photographic methods, whereby the coatinglocally dissipates its charge in proportion to the intensity ofillumination. Nonilluminated areas, which retain their charge, are thentreated with electroscopic powder (e.g., colored synthetic resins)resulting in a visible image which may be transferred to another surfaceor may be fixed, e.g., by fusing, rendering the powder permanentlyadherent to the coating substrate.

Fundamentally, then, electrophotographic coatings comprise aphotoconductor such as, for example, zinc oxide, which is bonded by anorganic resin to a base sheet or other substrate. It is known thatcopolymers of vinyl acetate and copolymers of styrene are individuallyeffective as binders. Coatings based upon vinyl acetate copolymers,however, have been found to be deficient in speed. Further, coatings ofcopolymers of styrene have been found to be low in charge acceptance andyield copies of poor image density. Both deficiencies of the separatecopolymers may be overcome, at least in part, by blending the two typesof copolymers. The major drawback of such blends, however, has beentheir incompatibility as exhibited by their rapid phase separation. Suchseparation is a serious drawback to commercial utilization. It might beexpected that compatible blends useful in this area could be achieved bythe mere matching of solubility parameters. Attempts to achieve this,however, have been unsuccessful. It is necessary for commercial utilitythat the blended resins be compatible in solution concentrations of atleast 20 percent by weight. Imposed upon this requirement forcompatibility, however, is, of course, the requirement that the blendemployed adhere to the particular photoconductive element being used inthe system and to the substrate as well. In addition, the binderemployed must enhance the photoconductive properties of the system.

SUMMARY OF THE INVENTION This invention relates to a composition ofmatter comprising a first interpolymer of at least one vinyl alcoholester and at least one ethylenically unsaturated acid ester and a secondinterpolymer comprising at least one vinylidene aromatic compound, atleast one ethylenically unsaturated acid and at least one ethylenicallyunsaturated compound containing at least one acid group.

More particularly, this invention relates to a composition of mattercomprising a blend of:

A. a first interpolymer comprising at least one vinyl alcohol ester andat least one ethylenically unsaturated acid ester containing at least 7carbon atoms and B. a second interpolymer comprising 1. at least onevinylidene aromatic compound,

2. at least one ethylenically unsaturated acid ester, and

3. 0.5 percent to 5.0 percent by weight, based upon the total weight ofthe second interpolymer, of at least one ethylenically unsaturatedcompound containing at least one acid group.

This invention also relates to the use of such blends in variousadhesive compositions wherein the term adhesive" is construed asincluding binders.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vinyl alcohol ester of thefirst interpolymer of the blends of this invention may be any vinylalcohol ester which is copolymerizable with the ethylenicallyunsaturated acid ester containing at least 7 carbon atoms. The choice ofthe particular vinyl alcohol to be employed will generally depend uponthe pigment which is to be included and the substrate to be coated. Thatis to say, the interpolymer produced should have the ability both to wetthe pigment and to adhere to the substrate. Examples of such vinylalcohol esters are vinyl formate, vinyl acetate, vinyl propionate, vinylbutyrate, vinyl pentanoate, vinyl hexanoate, vinyl heptanoate, vinyloctanoate, etc., their isomers and mixtures thereof. Where thecompositions of this invention are to be used as binders inelectrophotographic processes, it will usually be desirable that they beable to wet zinc oxide, a commonly used photoconductive pigment. Wherethis is the case it will generally be advantageous that a lower vinylalcohol ester e.g. vinyl formate, vinyl acetate, vinyl propionate, vinylbutyrate, or isomers thereof be employed. Thus, these four vinyl alcoholesters are the preferred vinyl alcohol esters in the practice of thisinvention. Vinyl acetate is most preferred because of its readycommercial availability and favorable capacity for interpolymerization.

A second component of the first interpolymer of the blends of thisinvention is an ethylenically unsaturated acid ester containing at least7 carbon atoms. It is this component that is critical to the attainmentof compatibility between the two interpolymers. Such esters may ofcourse be prepared by the reaction of organic acids and alcohols. Theacid moiety of such esters may be monocarboxylic, polycarboxylic,monosulfonic, or polysulfonic acids such as, for example, acrylic acid,methacrylic acid, maleic acid, fumaric acid, crotonic acid, vinylsulfonic and the like. The alcohol moiety of the ester may be anyalcohol containing sufiicient carbon atoms to bring the total number ofcarbon atoms of the ester moiety to at least 7. Thus the alcoholicmoiety may, for example, be methanol, ethanol, propanol, butanol,pentanol, hexanol, heptanol, octanol, etc., their isomers and mixturesthereof. Of those compounds which may be used as the second component ofthe first interpolymer, acrylic and methacrylic acid esters arepreferred, In particular, it has been found that butyl acrylate providesoptimal properties for electrophotographic coatings wheninterpolymerized with vinyl acetate and is thus the most preferredester.

In addition to the two critical components of the first interpolymerdescribed above, other monomers may be interpolymerized therewith toimpart particular desirable qualities to the resin. In particular, ithas been found beneficial and desirable in photoconductiveelectrophotographic applications that an ethylenically unsaturated acidester containing 4-6 carbon atoms be included, for example, methylacrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethylmethacrylate, and the like. Other esters such as dimethyl maleate,dimethyl fumarate and the like may be employed.

The vinyl aromatic compound moiety of the second interpolymer ispreferably styrene. However, ring-substituted styrenes in which thesubstituents are 1-4 carbon atoms alkyl groups or chlorine atoms may beemployed. Examples of such ring-substituted styrenes include ortho-,metaand paramethyl, ethyl, butyl, etc., monoalkyl styrenes, 2,3-2,4-dimethyl and diethyl styrenes; mono-, diand trichlorostyrenes alkylchlorostyrenes such as 2-methyl-4- chlorostyrene, etc. The use of two ormore such styrene monomer moieties is also within the scope of thisinvention. The ethylenically unsaturated acid ester which constitutes asecond component of the second interpolymer may be any alkyl ester of anethylenically unsaturated monocarboxylic or polycarboxylic acid, e.g.,methyl acrylate, methyl methacrylate, methyl crotonate, ethyl acrylate,ethyl methacrylate, ethyl crotonate, dimethyl maleate, dimethylfumarate, diethyl maleate, dipripyl itaconate, butyl crotonate, and thelike. The preferred ester is ethyl acrylate.

The second interpolymer further contains at least one ethylenicallyunsaturated compound containing at least one acid group. This acid groupmay be carboxylic acid group or a sulfonic acid group. Examples ofcompounds which may be employed are acrylic acid, methacrylic acid,crotonic acid, maleic acid, fumaric acid; monoesters and partialmonoesters of maleic acid, fumaric acid, itaconic acid, e.g., monomethylmaleate, monoethyl fumarate, etc., vinyl sulfonic acid, styrene sulfonicacid, sulfoethyl methacrylate, sulfoethyl acrylate, sulfoethyl maleate,and the like.

Any of various pigments may be dispersed in the compositions of thisinvention so long as it has adhesive affinity for the particularcomposition employed. By adhesive affinity is meant that the compositionwill adhere to the pigment and act as a binder therefor. Exemplary ofthe many pigments which might be used are titanium dioxide, ferricoxide, graphite, lead oxide, lead chromate and the like. Where thecompositions of this invention are to be used as binders inelectrophotographic processes the pigment will be one capable of beingrendered light sensitive by the application thereto of an electrostaticcharge. As examples of such photoconductors may be listed antimonyoxide, aluminum oxide, bismuth oxide, cadmium oxide, mercury oxide,molybdenum oxide, lead oxide, zinc iodide, cadmium iodide, cadmiumsulfide, selenium metal, arsenic trisulfide, lead telluride and thelike. In particular, zinc oxide is preferred for such application.Mixtures of two or more pigments may also be employed.

For such electrophotographic processes, various organic photoconductorsmay also be used either in addition to the inorganic, e.g. zinc oxide,or in place of them. Aromatic amines may, for example, be employed forthis purpose. Among the many that may be used are:4,5-Diphenyl-2-imidazolone, 4,5- dipheynlimidazole-Z-thione and theirderivatives, l-phenyl- 3,S-bis(p-methoxy-styryl) pyrazoline, polymers ofN-vinyl carbazole, 4,4"-dibromoterphenyl, poly(9-vinyl anthracend), etc.

The following examples are presented in illustration of the inventionbut are not to be construed as limitations thereof. Where parts arementioned, parts by weight are intended unless otherwise indicated.

EXAMPLE 1 Part A Into a reaction vessel equipped with an agitator, acondenser, a thermometer and a metering pump for controlled, delayedmonomer input is introduced 500 parts of vinyl acetate, 14 parts ofethyl acrylate, 14 parts of butyl acrylate, 140 parts toluene, parts ofbenzoyl peroxide and 2 parts of T-butyl perbenzoate. The mixture is thenheated to reflux. in a separate container is mixed 236 parts of ethylacrylate, 236 parts of butyl acrylate and 200 parts of toluene. Thismixture is then introduced into the reservoir supplying the meteringpump and addition of the delay and monomer charge is begun. The delay iscarried out over four 40-minute periods. During the first 40-minuteperiod 306 parts of the delayed monomer mixture is added, during thesecond 40-minute period 210 parts, during the third 40-minute period 107parts and, finally, during the last 40-minute period the final 50 partsof delay is added. The batch is then held at reflux for an additional 4hours. The solution is diluted with 230 parts of toluene and then cooledto room temperature. The resulting polymer containing solution has atotal solids content of 67 percent and a Brookfield viscosity (04spindle of 12 rpm.) of 36,000.

Part B Into a reaction vessel equipped as in Part A above is introducedparts of styrene, 250 parts of ethyl acrylate, 200 parts of toluene, 10part of acrylic acid and 4 parts of t-butyl perbenzoate. The batch isheated to reflux. A delay charge consisting of 75 parts of styrene,parts of toluene and 4.0

parts acrylic acid is mixed in a separate vessel. The delay is addedover a 4-hour period. During the first hour 136 parts of delay is added,during the second hour 67 parts, during the third hour 34 parts and,finally, during the fourth hour 17 parts. The batch is held at refluxfor an additional 16 hours and then cooled to room temperature yieldinga polymer solution having a total solids of 58.2% and a Brookfieldviscosity (04 spindle at 40 rpm.) of7,l00.

Part C Twenty parts of the 67 percent solids solution of Part A is mixedwith 23 parts of the 58 percent solids solution of the blends. Visualexamination shows that this solution blend is compatible.

Part D Sixty-eight parts of the 55 percent solution prepared in Part Cis weighed into a Waring Blende. One-hundred-forty four parts of tolueneis added and the new mixture is well agitated. Next is added 225 partsof a French process zinc oxide and agitation is continued at high speedfor 7-10 minutes. Four and one-half parts of a k percent solution inmethanol of a sensitizing dye is then added with thorough mixing. Thedispersion thus prepared is applied to a commercially availableconductive base-stock paper to a coating weight of 20 lbs. per ream. Thecoated paper is then dried and conditioned at 50 percent relativehumidity in the dark and then tested for charge acceptance, dark decaycharge and decay of charge during illumination using a Victoreen ModelEPA-825 electrostatic paper analyzer. The procedure by which this isaccomplished is set forth in RCA Review, Dec. l96l, pages 780-790. Forthe coating prepared in this example a charge acceptance is 440 volts,the dark decay of charge is 7.5 volts per second and the decay of chargeduring illumination is 104 volts per second.

EXAMPLE 2 Control Example 1 is repeated using the interpolymer ofexample 1, Part A and substituting for the interpolymer of example 1,Part B an interpolymer containing no acrylic acid, i.e., 50/50styrene/ethyl acrylate rather than 49/50/1 styrene/ethylacrylate/acrylic acid. The blended resin solutions are incompatible andno coating is obtainable upon which to test the electric properties.

EXAMPLE 3 Example I is repeated substituting for the interpolymer ofPart B an interpolymer of 49.5/50/0.5 styrene/ethyl acrylate/acrylicacid. Again, the blend is found to be compatible to toluene and theelectrical properties are: charge acceptance, 425 volts; dark decay ofcharge, 10 volts per second; and decay of charge during illumination, 94volts per second.

EXAMPLE 4 Example 1 is repeated substituting for the interpolymer ofPart B an interpolymer of 45/50/50 styrene/ethyl acrylate/acrylic acid.This blend is compatible in a solution with toluene and n-propanol andthe electrical properties are 515 volts charge acceptance, 5.0 volts persecond dark decay and 135 volts per second illuminated decay.

EXAMPLE 5 Example 1 is repeated except that a 60/40 vinyl acetate/butylacrylate copolymer is substituted for the 50/25/25 vinyl acetate/ethylacrylate/butyl acrylate interpolymer employed therein. The blend isfound to be compatible in toluene solution and the electrical propertiesare 441 volts charge acceptance, 7.0 volts per second dark decay and 86volts per second illuminated decay.

EXAMPLE 6 Control Example 1 is repeated except that a copolymer of 70/30vinyl acetate/methyl acrylate is substituted for the interpolymer ofPart A. This time the blend is incompatible in toluene solution and thecharge acceptance is only 166 volts. Dark decay is 5.0 volts per secondand illuminated decay is 94 volts per second. This example demonstratesthe deficiencies of a system not containing an ethylenically unsaturatedacid ester containing at least 7 carbon atoms as a part of the firstinterpolymer.

EXAMPLE 7 Into a reaction vessel is charged 180 parts styrene, 250 partsof ethyl acrylate and 1 part of 2-sulfoethyl methacrylate, 370 parts oftoluene and 8 parts of t-butyl perbenzoate. An additional 65 parts ofstyrene and 4 parts of sulfoethyl methacrylate blended with 5 parts oftoluene are added to the reaction in two separate streams over a 4-hourperiod while the batch is held at reflux. The reaction is maintained atreflux for an additional 20 hours and is cooled yielding a polymericsolution of 67.5 percent solids. The Brookfield viscosity is 1,600centipoises (03 spindle at 30 r.p.m.) The resulting interpolymer is thensubstituted for the interpolymer of example 1, Part B and the finalproduct is found to have a charge acceptance of 448 volts, a dark decayof 4.0 volts per second and an illuminated decay of 107 volts persecond.

EXAMPLE 8 Example 1 is repeated except that an interpolymer of 40/50/ 3chlorostyrgnelethyl acrylate/acrylic acid is substituted for theinterpolymer of Part B. The blend is again found to be compatible intoluene and the electrical properties are 177 volts charge acceptance,4.5 volts per second dark decay and 87 volts per second illuminateddecay.

It will be noted that in the foregoing examples the first and secondinterpolymers have been blended in 1:1 ratios. It is not necessary tothe practice of this invention that such be the case. The 1:1 ratio waschosen as being the most rigorous test of compatibility; that is to say,if compatibility can be shown at 1:1, it will also be achievable whereone or the other of the components is present in major proportions. Forparticular applications as, for example, in electrophotographyoptimization of a particular system well may dictate variations inproportion as divergent as 9:1 or 1:9 or even beyond.

Further, it should be noted that although the examples show onlyapplication to paper substrates, they may also be successfully appliedto metal, glass, ceramics and, in particular, wooden substrates. Thus,upon formulation with the various pigments, fillers, driers, extenders,dyes, etc. well known to those of skill in the art, paints and othercoatings for application to a wide variety of surfaces may be produced.

Thus, it will be obvious that many variations and modifications may beapplied to the invention described herein without departing from thescope thereof.

What is claimed is:

1. An article of manufacture comprising a substrate having depositedthereon a blend consisting essentially of:

A. a first interpolymer consisting of an interpolymerization product ofat least one vinyl alcohol ester and at least one ester of acrylic acidcontaining at least 7 carbon atoms and B. a second interpolymerconsisting of an interpolymerization product of:

l. at least one vinyl aromatic compound,

2. at least one ester of acrylic acid and 3. 0.5 to 5.0 percent byweight, based upon the total weight of the second interpolymer, of atleast one ethylenically unsaturated compound containing at least oneacid group;

wherein the weight ratio of the first interpolymer to the secondinterpolymer is in the range of from 9: 1 to 1:9.

2. The article of claim 1 wherein the first interpolymer consistsessentially of an interpolymerization product of:

A. at least one vinyl alcohol ester,

B. at least one ester of acrylic acid containing at least 7 carbon atomsand C. at least one ester of acrylic acid containing 4-6 carbon atoms.

3. The article of claim 1 wherein the interpolymer blend deposited onthe substrate has dispersed therein at least one pigment having adhesiveaffinity for the blend.

4. The article of claim 1 wherein the substrate comprises a cellulosicmaterial.

5. The article of claim 4 wherein the cellulosic material is paper.

6. An article of manufacture comprising a substrate having depositedthereon a blend consisting essentially of:

A. a first interpolymer consisting of an interpolymerization product ofvinyl acetate and at least one ester of acrylic acid containing at leastseven carbon atoms and B. a second interpolymer consisting of aninterpolymerization product of:

1. styrene,

2. at least one ester of acrylic acid and 3. 0.5 to 5.0 percent byweight, based upon the total weight of the second interpolymer, of atleast one ethylenically unsaturated compound containing at least oneacid group;

wherein the weight ratio of the first interpolymer to the secondinterpolymer is in the range of from 9:1 to 1:9.

7. The article of claim 6 wherein the first interpolymer consistsessentially of an interpolymerization product of:

A. vinyl acetate,

B. butyl acrylate, and

C. at least one ester of acrylic acid selected from the group consistingof methyl acrylate and ethyl acrylate.

8. The article of claim 6 wherein the interpolymer blend deposited onthe substrate has dispersed therein at least one pigment having adhesiveaffinity for the blend.

9. The article of claim 6 wherein the substrate comprises a cellulosicmaterial.

10. The article of claim 9 wherein the cellulosic material is paper.

11. An article of manufacture comprising a substrate having depositedthereon a blend consisting essentially of:

A. a first interpolymer consisting of an interpolymerization product ofvinyl acetate and butyl acrylate; and B. a second interpolymerconsisting of an interpolymerization product of:

1. styrene,

2. at least one ester of acrylic acid and 3. 0.5 to 5.0 percent byweight, based upon the total weight of the second interpolymer, of atleast one ethylenically unsaturated compound containing at least oneacid group;

wherein the weight ratio of the first interpolymer to the secondinterpolymer is in the range of from 9:1 to 1:9.

527; UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIGN Patent No,3,6O7r376 Dated Sepl'ember Zl, E97! Roberr 8. Bl ance, David R. Cahi ll& Pei'er Wach-l-el Inventofls) It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 3, I ine 8, diprlpyl" should read dipropyl Column 3, l ine 75 "(04 spindle f 12 r.p.m. should read (#4 spindle a1 12 r.p.m.)

Column 4, line 16, "(0 4 spindle al' 4L9 r.p.m. should read (#4 spindleal" 4Q r.p.m.)

Column 4, l ine 20, delei'e "The word "The" a; "me end of l'hesenl'ence. Column 4, I ine 2i before "blends" add l-he fol lowing Perl"8 and 5.7 par'ls of 'i'oluene is added 'l'her'el'o +0 yield a 55% solids soluTion of rhe Column 4, l i ne 27, "Blende" should read BlendorColumn 5, l ine 34 "(0 3 spindle al 3O r.p .m. i shoul d read (#3spindle a1 30 r.p.m.)

Signed and sealed this 25th day of April 1972 (SEAL) At'test:

EDWARD M.FLI"3HER,JR. ROBERT GOTTSCHALK Attesting Officer CommissionerofPatents

2. at least one ester of acrylic acid and
 2. at least one ester of acrylic acid and
 2. The article of claim 1 wherein the first interpolymer consists essentially of an interpolymerization product of: A. at least one vinyl alcohol ester, B. at least one ester of acrylic acid containing at least 7 carbon atoms and C. at least one ester of acrylic acid containing 4-6 carbon atoms.
 2. at least one ester of acrylic acid and
 3. 0.5 to 5.0 percent by weight, based upon the total weight of the second interpolymer, of at least one ethylenically unsaturated compound containing at least one acid group; wherein the weight ratio of the first interpolymer to the second interpolymer is in the range of from 9:1 to 1:9.
 3. The article of claim 1 wherein the interpolymer blend deposited on the substrate has dispersed therein at least one pigment having adhesive affinity for the blend.
 3. 0.5 to 5.0 percent by weight, based upon the total weight of the second interpolymer, of at least one ethylenically unsaturated compound containing at least one acid group; wherein the weight ratio of the first interpolymer to the second interpolymer is in the range of from 9:1 to 1:9.
 3. 0.5 to 5.0 percent by weight, based upon the total weight of the second interpolymer, of at least one ethylenically unsaturated compound containing at least one acid group; wherein the weight ratio of the first interpolymer to the second interpolymer is in the range of from 9:1 to 1:9.
 4. The article of claim 1 wherein the substrate comprises a cellulosic material.
 5. The article of claim 4 wherein the cellulosic material is paper.
 6. An article of manufacture comprising a substrate having deposited thereon a blend consisting essentially of: A. a first interpolymer consisting of an interpolymerization product of vinyl acetate and at least one ester of acrylic acid containing at least seven carbon atoms and B. a second interpolymer consisting of an interpolymerization product of:
 7. The article of claim 6 wherein the first interpolymer consists essentially of an interpolymerization product of: A. vinyl acetate, B. butyl acrylate, and C. at least one ester of acrylic acid selected from the group consisting of methyl acrylate and ethyl acrylate.
 8. The article of claim 6 wherein the interpolymer blend deposited on the substrate has dispersed therein at least one pigment having adhesive affinity for the blend.
 9. The article of claim 6 wherein the substrate comprises a cellulosic material.
 10. The article of claim 9 wherein the cellulosic material is paper.
 11. An article of manufacture comprising a substrate havinG deposited thereon a blend consisting essentially of: A. a first interpolymer consisting of an interpolymerization product of vinyl acetate and butyl acrylate; and B. a second interpolymer consisting of an interpolymerization product of: 